Yes, I have noticed difficulty going up as well.  To be expected!

Even still, with money flowing into Alt coins I think mining will continue to be profitable even for GPU mining without a custom rig. Who knows, but looking at the current numbers I think I'll be able to at least break even. You can look at threads from early november talking about GPU mining being dead and not worth it, but with the rise in alt coin pricing I don't think that's the case anymore.

I think if you believe alt coins will have a place in the market going forward (which I do) then mining is worth the gamble.